Deathbringer - CR 18 (Large Undead)

When you reach the epic tier in 5th Edition, you need a accept that you are going to face some badass enemies. These hulks, pulled from the 3.0 Monster Manual II are just that - undead tanks, that can steamroll a party, heal their allies and still find enough things to do to keep your high level heroes more than busy just trying to stay alive.

Created or summoned by Liches and other potent dark masters, these brutes tower almost 12 feet in height, and strike at enemies with their hideous bone flails. Only the strongest or bravest souls will try and take one on - and they are often met in groups....

 "I've come about the flailin'"